Distillation of hydrocarbon oils



n Dec- 9 1930. G. w. WATTS ET AL 1,784,561

DISTILLATION OF HYDROCARBON OILS Filed April 3, 1925 2 Sheets-Sheet lSEPRA TR Dec. 9, 1930. 4G. w. wms T A.. 1,784,561

DISTILLATION OF HYDROGARBON OILS Filed April 5, 1925 2 Sheets-Sheet 2Patented Dec. 9, 1930 UNITED STATES PATENT OFFICE GEORGE W. WATTS,PHILIP L. IKRAUELQAND THOMAS E. STOCKDALE, F WHITING,

INDIANA, ASSIGNORS T STANDARD OIL COMPANY, 0F WRITING, INDIANA, A COR-.

PORATION OF INDIANA DISTILLATION 0F HYDROCARBON OILS Application ledApril 3,

The present invention relates to improvements in the distillation ofhydrocarbon oils, and is more particularly intended for use inconnection with the distillation under vacuum of heavy oils, such' asthe residues derived from the continuous distillation of crude oil withfire and steam. It will be fully understood from the followingdescription, illustrated by the accompanying drawings, in which:

Figure 1 is a diagrammatic view, partly in section, of apparatussuitable for carrying the invention into effect; and

Figure 2 is a sectional view through the heating or interchange deviceused in carrying out the present invention.

In carrying out the invention, the oil to be distilled is supplied tothe system through a pipe 5, the oil suitably coming directly from thelast still of continuous battery of tire and steam stills, for example,as described in the U. S. patent to one of us, No. 1,689,606.Superheated steam, suitably at atmospheric pressure, is supplied throughthe pipe 6, and enters the expanding nozzle 7, through which it passesinto the conduit 8, which is maintained under sub-atmospheric pressure.In the nozzle 7 the steam is expanded to about the reduced pressureprevailing in the conduit 8. The oil, supplied through the pipe 5, flowsthrough a small feed pipe or conduit 9 (see Fig. 2), which enters thesteam expanding nozzle 7, being preferably placed centrally therewithinand spaced from the walls of the nozzle.- The feed conduit 9 ter-lminates beyond the throat of nozzle 7, being provided therein withdistributing openings 10, suitably located at such a point in the nozzlethat the temperature of the steam is already appreciably reduced, asmore fully pointed out hereinafter. The oil is atomizedv and carriedforward in a spray by the expanding steam, entering the conduit 8. Infront of the opening 11 of the nozzle 7 there may be suitably placedwithin the conduit 8, a deflector 12, mounted upon a spider 13. Thedelector 12 directsA the projected spray toward the walls of the conduit8, thereby preventing its passage through any substantial portion of theconduit in the form of a 1925. Serial No. 20,414.

solid stream or spray. Within the conduit 8 the oil, steam and vaporQuickly assume a steady flow at a rate predeterminedl by the dimensionsof the cnduit. The length of the conduit 8 is sufficient to permit themixture of oil, steam and vapor to attain thermal equilibrium, thedesiredproportion of the oil being vaporized. From'the conduit 8,`thevapors and oil enter the 'separator 14, in which the unvaporized oil isseparatedfrom the vapors present, preferably substantiallywithout-change in velocity of the latter. As more fullydesoribed in theU. S. Patent No. 1,751,182 to Robert E. Wilson, the conduit contains aplurality of helical vanes or an Archimedean screw, which issubstantially fixed in position and extends wholly or partly through theconduit 14. Thus, the mlxture of the vapors and unvaporized liquid isgiven a rapid rotating or whirling movement, thereby throwing out uponthe walls of the conduit 14 the unvaporized liquid, which drains offthrough the pipe 15. The unvaporized oil collected in the separator 14is discharged through the conduit 15 provided with a trap 16 and acontrol valve 17, into a receiver 18. From the separator the va pors,consisting of the vaporized portions of the oil and steam, pass throughconduit 19 into the condensing chamber20, in which the vapors arecooled, for example, by the cooling coils 21, to which a suitablecooling medium, such as water or oil, is supplied through the valvedpipe 22.

The condenser 20 is preferably so controlled as to condense the oilvapors without condensing the steam accompanying them. Uncondensedvapors are collected by any suitable means, for example, the invertedhood 23 and pass out through conduit 24 and separator or trap 25, inwhich entrained condensate is separated. Condensate formed in thecondenser 20 is drawn oil' through the valved pipe 26 and passes intothe receiver 27. Condensate trapped out in the separator 25 passesthrough valved pipe 28 into the pipe 26 leading to the condensatereceiver 27. The steam continues from the separator 25 through pipe 29to the condenser 30, in which it is condensed, and the resultingcondensate passes out through pipe 31 into a suitable receiver 32. Thereceivers 18, 27 and 32 are connected by lines 33 to the intake pipe-34of the vacuum pump 35, by which the desired 'vacuum is maintained uponthe system.

In carrying out the invention the oil to be distilled, suitably aresidue from the continuous lire and steam distillation of a. crude oil,is fed to the system through the pipe5, preferabl directly from thecontinuous battery in wliich the distillation of the crude is effected.For example, the stock employed may be such a residue representing thefinal 20% of a mid-continent crude and having a temperature of 650 to 750 F., (substantially the temperature prevailing in the last still ofthe battery from which it is derived). Superheated steam, for example,at 900 to 1200 F. and at atmospheric pressure is supplied to the systemthrough the pipe 6. The amount of steam supplied is proportioned to theextent to which it is desired to conduct the distillation of the oilundergoing treatment, and may suitably' be from 2 to 10 pounds pergallon of oildistillate. For example, in order toeiect the distillationof an oil such as that hereinbefore described-to a 20% residue(amounting to l to 5% on the original crude), from 4 to 5 pounds ofsteam per gallon of oil distillate may be employed under the conditionsmore specifically hereinafter set forth.

Within the conduit and in the remainder of the distillation process asubstantially reduced pressure is maintained, preferably from 25 to 75millimeters absolute. In its passage through thg nozzle 7, the pressureupon the steam is reduced and it is propelled forward at a highvelocity. The reduction in pressure is accompanied by a drop in temperature, the oil inlet openings 10 being so located that thetemperature of the steam at that point is not in excess of 900 F., andpreferably between 325 and 650 F. The oil 1s finely subdivided by therapidly traveling stream of expanding steam, this stream being forcedoutward and prevented from traveling as a solid stream of spray by thedefiector l2. The spray or mixture of oil and steam resumes steady flowthrough the conduit 8, which is so proportioned thatthe velocity of thesteam therethrough, in stead How, is from 200 to 600 feet per second,pre erably about 400 feet per second. In resuming steady flow at thisrate, suicient heat reverts to the body of steam and oil to bring themixture to a temperature of 650 to 750 F. and to supply the latent heatnecessaryfor the vaporization of the desired portions of the oil. Theconduit 8, which may be designated as an equilibrium conduit, is ofsufficient lendgth to permit the mixture of steam, oil an vapor to cometo substantial equilibrium, this being accomplishedin a travel of from lone-fifteenth to one second. The' mixture of is maintained at a suitabletemperature to effect condensation of the oil. The condensed oildischarges through the line 26 into the vented container27. Uncondensedsteam, together with any entrained oil carried thereby, passes outthrough the collector 23 and line 24 into and through the trap orseparator 25, in which the entrained oil is separated out and returnedto the line 26 through the line 28. Distillate is collected in thereceptacle 27, from which it may be discharged 'at will through the line37. The steam passes out. through the condenser 30 and the condensedwater is collected in the receiver 32. The distillate produced ischaracterized in that it contains etrolatum wax, substantiallyunchanged, an a typical distillate on a residuum on such as thatpreviously described (amounting t'o 16% on the original crude) has thefollowing characteristics:

22.6 A. P. I. gravity; Hash. 390 F.; 72 sec. Saybolt viscosit at 210 F.;solid at 90o F. The residuum ormed in the same process, amounting to 4%on the original crude, is found to have a melting point of about 196 F.,a gravity of 1.07 at 7 4 F., a viscosity of 90 Engler at about 350 F..and to contain 96 to 98% of carbon tetrachloride and carbon di-suldesoluble constituents.

IVe claim: l

1. The method of distillation of hydrocarbon oils comprising supplyingsuperheated steam to a gradually expanding passage, the temperature ofthe steam being reduced as it travels therethrough, supplying oil to theat least partially expanded steam where the temperature of the steam isless than 900 F., discharging the steam and oil carried thereby into aconduit at reduced pressure, said conduit being of substantially largercross section than the passage, a'nd causing the mass of vapors `and oilto )pass in steady flow through said conduit without substantialseparation of oil and'vapor therein.

2. The method of distillation of hydrocarbon oils comprising-supplyingsuperheated steam to a gradually expanding passage, the temperature ofthe steam being reduced as it travels therethrough, su plying oil to theat least partially expande steam where the temperature ofthe steam isless than900 F., discharging. the steam and oil carried thereby presserdirectly into a conduit at reduced pressure, said conduit -heing otsubstantially larger cross-section their. seid passage, and causing themass of vapors .and oil to pass in steady Lilou* through said conduitWithout substantial separation ot oil and ynpor therein.

3. The method oit distillation of hydro-carhon oils comprising supplyingsuperheated steam to u gradually expanding; passage, the temperature otthesteam losing reduced as it travels therethrough, supplying oil to theexpanding steam before complete expansion and wnere the temperature ofthe steam is less than 900 ll., and discharging the steam and. oilcnrried thereby into en enlarged chamber at reduced pressure.

l. The method oi distillation oi hydrocarhon oils `wherein superheatedsteam is expanded in gradually expandingl presagi-e, its temperatureheingr reduced .sf-s it travels therethrough., oil is supplied to saidpassage at a point therein 'where the temperature ot the steam is lessthan 900 ll., the mixture olf steam and oil carried therehy is caused toflow without separation through a conduit under said reduced pressure eta rate substantially less thun the velocity ot issuance ot the steam undoil Jfrom said expanding conduit,

heut heine therehy applied to the mixture of steam und oil, andunvaporized oil is subsequently separated from the steam and vaporizedoil.

5. The method ot distillation of hydrocarlion oils wherein superheatedsteam at a'temperature ot 900O to 12000 ll. is expanded in s gfrnduullyexpanding passage, its temperature being reduced as it travelstherethrough, oil is supplied to said conduit :it a point therein wherethe temperature oi the steam is less than 900o F.. the mixture oi steamand oil carried thereby is caused to dow without separation through aconduit under reduced pressure at a velocity ot 200 to 600 feet persecond, heat thereby reverting to the mixture of steam and oil, andunyaporized oil is suhsequently separated from the steam and ysporizedoil.

6. rll`he method of distillation of hydrocarloon oils, which compriseserpandinle,r superhented steam through an expanding passage into uconduit of substantially greater crosssertionul uren, the temperature ofthe. steam seing reduced in truyelinpr through the expanding passage,feeding oil into the stream or? steein in the expanding passage at apoint where the temperature of the steam is Jfrom 325 to 900 iF.,causing the steam and oil minture to den' stendily without substantialseparation through the conduit into which expanding passage opens at arate suhstantiolly less than the velocity ot issuance ot the steuin andoil troni said expanding conduit, heut being thereby supplied to themixture oi: steam and "vapor, and separating unyapo'rized oil from saidmixture Without suhstantial decrease in its velocity of flow.

7. ln apparatus for the distillation of hydrocsrhon oils, an expandingnozzle pro- 'vided with a constricted throat, means for passingsuperheated steam through the throat or" said nozzle, and means forsupplying oil within the nozzle to the steam alter the steunt passes thethroat of said expanding nozzle.

8. ln apparatus for the distillation of hydrocsrhon oils, an expandingnozzle having a constricted throat, s conduit of larger crosssectionalarea than said expanding nozzle into which the .nozzle opens, means forsupplyinp; superheated steam to said expanding nozzle, meansiorsupplying oil Within the nozzle to the expanding steam after ythesteam passes the throat of said expanding nozzle, and means tormaintaining a reduced pressure within the enlarged conduit.

9. ln apparatus -for the distillation oi hydrocarbon oils, an expandingnozzle, means for supplying superheuted steam to said nozzle, u conduitof larger cross-sectional arca into which said nozzle opens, saidconduit being maintained ut reduced pressure, an oil leed pipe extendinglongitudinally' through said nozzle and provided with exit openings atan intermediate point therein, und means for supplying' oil to seid feedpipe.

10. ln apparatus for the distillation of hydrocarbon oils, an expandingnozzle, means tor supplying superheated steum to said nozzle, a conduitot' larger cross-sectionsl area into which said nozzle opens, saidconduit heingi' maintained at reduced pressure, means for supplying oilWithin said nozzle Where the steam is ut least partially expended, andmeans 'Within the conduit lor diverting;7 transversely the projectedstream ot vapor and oil issuing; `from the nozzle, the stream ot vaporand oil continuing to travel through said conduit beyond said divertingmeans, wherehy intimate intermiirture thereof is ellected. v

ll. ln the vacuum distillation ot hydrocarbon oils, expandingsuperheated steam through an expanding passage into an enlarged conduitut reduced pressure, supplying oil to the at least partially expandedsteam before entering seid conduit, impinning the mass of vapor and oilparticles against a surtace within said conduit and subsequently causingthe mass ot `vapor and oilparticles to move forwardly through theconduit in steady llora at a rate ot at least 200 toet per second.

GEORGE W. WATTS PHlllillFD L. lltRlUElli. THOMAS E. STCKDALE.

lllli

